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Convert MKV to MP4

Free MKV to MP4 converter that runs in your browser. No upload, no signup, no watermark. Files never leave your device.

Conversion Successful
100% local. Your file is processed in this tab and never uploaded.

How to Convert MKV to MP4

Four steps. No uploads, no account, no waiting.

1

Upload your MKV file

Drag and drop your MKV file into the converter above, or click to browse and select it from your device. Files stay on your machine and are never uploaded to a server.

2

Select MP4 as the output format

Open the output format picker and choose MP4. The converter automatically detects the input and only shows compatible output formats for your file.

3

Adjust settings (optional)

Use the sliders icon to trim, crop, resize, rotate, mute or rebalance audio, and pick an output quality before converting.

4

Convert and download

Click Convert to run the conversion in your browser. The output MP4 file downloads automatically when ready, with no server round-trip and no watermarks.

Why Convert MKV to MP4?

MKV is a popular container for high-quality video with multiple subtitle and audio tracks, but it does not play on most smart TVs, iOS devices, PlayStation, or streaming services without a dedicated media app.

Converting to MP4 creates a broadly compatible file that plays natively on every device.

MKV
MP4
Container
Matroska (MKV)
Container
MP4 (ISOBMFF)
Typical codec
H.264 / H.265 / AV1
Typical codec
H.264 / H.265
Audio codec
AAC / AC3 / DTS / FLAC
Audio codec
AAC
Streaming friendly
No
Streaming friendly
Yes
Device support
PC media players, limited TVs
Device support
Universal
Typical use
HD/4K video archives
Typical use
Web, mobile, TV

Related Conversions

Other common format conversions you might need.

AVI to MP4
Convert AVI files to MP4
WebM to MP4
Convert WEBM files to MP4
MOV to MP4
Convert MOV files to MP4
MP4 to MP3
Convert MP4 files to MP3

Frequently Asked Questions

My MKV has multiple audio tracks. Which is extracted?
The browser converter extracts the default audio track (usually track 1, often English). TeraConvert Desktop lets you choose which audio and subtitle tracks to include.
Will my MKV subtitles transfer to the MP4?
The browser tool does not preserve subtitle tracks. TeraConvert Desktop transfers embedded subtitle tracks to the MP4 container.
My MKV uses H.265 (HEVC). Will the MP4 also be H.265?
The output targets H.264 for maximum compatibility. H.265 sources are re-encoded to H.264, which may slightly increase file size at the same visual quality.
Can I convert a 1080p or 4K MKV file?
Yes. The browser tool supports up to 500 MB files. For large 4K MKV files (often 20-40 GB), TeraConvert Desktop handles them natively with hardware acceleration.
Is this conversion really free, and is my file private?
Yes. The browser conversion runs entirely on your device using WebAssembly. Files are never uploaded to a server and are discarded from memory when you close the page. There is no file size tracking, no account link to your upload, and no cloud storage.
Do I need to create an account to convert files?
No. The browser converter works without signing in. An optional account is only needed if you want to save favorites, track conversion history, or upgrade to the desktop app with Polar license activation.
How fast is the conversion?
Most browser conversions complete in a few seconds. Large files (over 100 MB) or heavy formats (video, high-page PDFs) take longer depending on your device's CPU and available memory. The desktop app runs significantly faster using native engines.

Convert MKV to MP4 Faster with TeraConvert Desktop

Batch files. No size limits. Native engine. No browser tab.

Batch convertNo size limitsNative speed100% private
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